Networks that work well serving data to desktop computers from internal servers may slow to a crawl with the use of applications based on the Web

Less processing on the users' PCs means more demand on network servers and on the network itself. More processing requests, more data being transferred. When PeopleSoft rolled out PeopleSoft8 internally, adjustments had to be made to network infrastructure. "Within the firewall, compared to the client/server architecture, there is more trafficyou're going to the server more, so there is more traffic," says Ram Gupta, executive vice president of products and technology at PeopleSoft. Application performance is tied to your network's bandwidth and throughput as much as processing power. To reduce that dependency, PeopleSoft and other vendors are trying to deliver more code down to the desktop, through use of dynamic HyperText Markup Language and Java applets, which allow some functions like data validation and calculations to be run on users' browsers.

If you've customized client/server systems, portals may be a pain

Because earlier versions of SAP, PeopleSoft and other enterprise software packages were designed around a set of "vanilla" business processes, many customers made major modifications to the software packages to bring them more closely in line with their requirements. But migrating to portals may break a lot of that work. Some PeopleSoft8 users have experienced major difficulties, because they can't just plug their prior custom pieces of code into an upgrade. Since PeopleSoft8 is essentially a complete rewrite of the product, the code built by customers can't easily be ported over to the new systemwhich has caused frustration. Gupta recognizes this. "Based on how much customization you've done in the past, the more challenging an upgrade becomes. The trouble has been with people who've done lots of customization." But Gupta says that many of the functions customers built in-house have now been added into the product.

The migration problem is less of an issue for SAP customers moving from R/3, since R/3 is part of mySAP. However, customers may still have to change some settings to connect them to newer features of the software. The real challenge is moving customized processes from SAP R/2 (a mainframe-based product) to mySAP and R/3which would essentially require a major rewrite.

Some portals are storage hogs

Using Web browsers means more data gets stored back on the serverin some cases, a lot more. That's because additional information and application code that used to be in software on laptop and desktop computers must be stored for each user account in database tables on the server, as well as information about custom views of enterprise data.

Lance Travis, analyst at AMR Research, says moving to mySAP.com can increase required storage on the server by 30% to 50% over SAP R/3 "just to duplicate what you had before." That can add up to hundreds or thousands of additional gigabytes of disk storage. But SAP officials say that most users will experience a great deal smaller growth in storage requirementsusually from 0 to 5%. Customers may see spikes in storage needs because of the additional features built into the mySAP platform that were optional with earlier R/3 implementations, such as the business information warehouse.

Moving to a Web-based version of an old product means new technologyand new problems

Transactions in a client-server environment are, while not child's play, fairly well understood. But doing transactions using the Web is another matter. As companies try to take advantage of technologies like Web services and electronic marketplaces, they may hit some trouble.

"SAP Internet Transaction Server [ITS] is very difficult to deploy; we've heard of very few people who've successfully deployed it," says AMR's Travis. "Lots of people have taken six, nine, or 12 months to roll it out, and have never deployed it correctly. It's a difficult area to get up and running correctly." He points to the complexity of the configuration and problems with the reliability of ITS as the main barriers. SAP officials, however, say SAP customers haven't had major problems with ITS, and that there has been no significant negative feedback about the software.

Sean Gallagher is editor of Ziff Davis Internet's enterprise verticals group. Previously, Gallagher was technology editor for Baseline, before joining Ziff Davis, he was editorial director of Fawcette Technical Publications' enterprise developer publications group, and the Labs managing editor of CMP's InformationWeek. A former naval officer and former systems integrator, Gallagher lives and works in Baltimore, Maryland.